Improvement in pulley-blocks



Patentedlan. 5,1875.

W El R, r

Pully-Blocks.

Wfmessem .UNITED STATES PATENT OFFICE.,

JOHN WEIR, OF NEW YORK, N. Y.

IM PRQVEMENT IN PU LLEY-BLOCKS.

Specification forming part of Letters Patent No. 158, 148, dated January 5, 1875; application filed December 12, 1874.

To all whom it may concern:

Be it known that I, JOHN YVEIR, of the city, county, and State of New York, have invented certain Improvements in Pulley Blocks, of which the following is a specification:

The principal object of my invention is to construct a cheap and durable block for general light purposes, although the prinoipie of Construction may be adapted to those used in hoisting heavy articles as well, because of its simplicity and strength.

In the drawings, Figure l is a perspective view of my invetion. Fig. 2 is a longitudnal vertical section of the same through the line of the center of the sheave-axis.

Let A A represent the cheeks of an ordinary wooden block, connected at the ends by separate pieces, or the entire 'block may be made from one piece of wood, and mortised to receive an ordinary wood or iron sheave, B. This sheave is hnng on a metal pin or axle, a, passed through the checks of the block, and terminatng at the outer surface of the same.

The important feature of my invention consists in a novel U-shaped bail, O, by which the block maybe Suspended. The arms of this bail are let into the checks of the block fiush, or nearly so, with the surface of the same. From the point b where the arm eters the wood to the center of the block, where it terminates in a circular boss, c, it has a gradual taper on both sdes, being widest where it joins the boss. In the centers of these bosses c c the ends of the pin or axie co terminate, and are stron gly riveted.

The bosses c c may be polygonal in form; but I prefer to make them cir'cular, for the reason that it is easier to cut the wood away for their admission in this form than any other.

The object in giving taper to the arms of the baii G and providing the bosses o c is, to relieve the pin a of a portion of the strain in lifting. The taper of the arms acts as a dovetail, and the angle formed by the bosses c c with the tapered portions of the arms abuts against the wood of the checks, and assists in supporting the weight.

By permitting the arms of the bail C to extend only to the center of the sheave, or far enough to receive the pin on which the sheave turns, I save nearly one-half of the metal that would be required if a band were passed entireiy around the block in the usual manner.

By riveting the pin a firmly at both ends into the bosses c o the block is firmly braced laterally.

I claim as myinvention 1. The U-shaped bail C, having tapered or fiared extremites, embedded into the Wood of the block, the said extremities reeeiving the riveted ends of the sheave-axle a, substantialiy in the manner shown, and for the purposes specified.

2. The U-shaped bail C, having tapered or flared extremities, with circular or poiygonal bosses c c, to receive the riveted ends of the sheave-axle a, when the said extremities and bosses are embedded into the Wood of the block, nearly or quite flush with the same, substantially in the manner shown, and for the purposes set forth.

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

JOHN VVEIR.

Witnesses:

HENRY GONNETT, ARTHUR G. FRASER. 

